Helped me for my class

This is an important book, but unfortunately it was scanned sideways. I would recommend using a PDF viewer which can rotate the pages to the correct orientation in order to be able to read it properly.
Also, the pages were not digitally split, so every page in the PDF shows both pages. I would recommend this scan instead, which is both scanned upright and has digitally split pages: https://archive.org/details/CommunismInGermany1933
However, one point in favor of this scan is that the image quality is very good, better than the other one I linked to. So if you can rotate the pages, then this is a good scan for viewing the high-quality images.
I would say 5 stars for the book itself, but 3 or 4 stars for the scanning because it has all the content, but is inconvenient for digital reading unless you can correct the orientation. Not to mention the lack of digital splitting. But I do have to admit that it has high image quality.